1. Field of the Invention
The present invention generally relates to a brake pad. More specifically, present invention relates to a disk brake pad of a disk brake apparatus used for a bicycle.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle braking system.
Disk brake pads generally grip a disk brake rotor that rotates with a wheel for stopping rotation of the wheel. Conventionally known disk brake pads of this type have a dry friction member made of a sintered copper metal and a backplate made of a stainless steel alloy or other steel to which the friction member is joined (for example, see Japanese Laid-Open Patent Application No. 08-188769). In conventional disk brake pads that have a friction member made of such a sintered metal, the friction member is manufactured by diffusion bonding, whereby the sintered metal is baked and simultaneously joined to the backplate. Specifically, a copper plating is formed on the bonding surface of the backplate, a molded metallic compact that will become the friction member is placed on the copper plating layer, and the compact that will become the friction member is joined to the backplate by being baked using a hot press at a high temperature of, e.g., 900° C. For brake pads manufactured in this manner, the bonding of the friction member to the copper plating layer is performed using chemical bonding, with the backplate and the copper plating layer being metallically bonded.
In a conventional configuration in which the friction member is bonded on the copper plating layer through diffusion bonding, the copper plating layer that is chemically bonded to the friction member is first formed on the backplate, and then the friction member is subsequently sintered thereon. It accordingly becomes necessary to have a pretreatment step for forming the copper plating layer on the backplate surface, and to have equipment for applying pressure during the heat treatment and for performing diffusion bonding. The manufacturing steps become complicated.
Diffusion bonding requires a high temperature of 850° or higher. The baking temperature rises during sintering, and the hardness of the friction member increases, so that noises may be produced during braking.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved bicycle disk brake pad. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.